OBJECTIVETo observe the effects of hemoperfusion on plasma concentration and histopathological changes in paraquat (PQ) poisoning rabbits.

METHODSSixteen rabbits were randomly divided into exposure group (PQ group, n = 8) and hemoperfusion plus PQ exposure group (HPQ group, n = 8). HPQ group were given hemoperfusion in 45 min after exposure to PQ. The plasma PQ concentrations at 0.5, 1.0, 1.5, 2.0, 3.0, 6.0, 12.0, 24.0, 48.0 and 72.0 hours after exposure were measure in 2 groups. The histopathological changes of lung, liver and kidney were examined, the behavior changes and the survival number of 7 days were observed.

RESULTSThe poisoning symptoms of HPQ group were generally better than those of PQ group, in each group six animals survived for 7d. The plasma PQ concentrations at 1.0, 1.5, 2.0, 3.0, 6.0, 12.0, 24.0, 48.0, 72.0 h after exposure in HPQ group were significantly lower than those in PQ group (P < 0.05 or P < 0.01). In HPQ group, the plasma PQ peak concentration [(5.01 ± 0.15] µg/L], area under the curve [(54.03 ± 5.31) mg×h(-1)×L(-1)] and PQ half-life time [(16.29 ± 3.26) h] after treatment of HP were significantly lower than those [(11.97 ± 0.75) µg/L, (141.40 ± 10.10) mg×h(-1)×L(-1) and (31.16 ± 9.85) h] in PQ group (P < 0.05). The apparent volume of distribution and PQ clearance rate in HPQ group were significantly higher than those in PQ group (P < 0.05). Congestion, edema, cell infiltration and other pathological changes were found in lung, liver and kidney in PQ group under the light microscope, which were significantly more severe than those in HPQ group. The pathologic scores of lung tissue, liver and renal tubular damage on the 1st, 3rd, 7th days after exposure in HPQ group were significantly lower than those in PQ group (P < 0.05).

CONCLUSIONWhen acute PQ poising, rabbits appeared the quick absorption, high toxicity and long half-life time of PQ. The early hemoperfusion can effectively remove the toxicant in plasma and reduce the pathological injury in major organs, which may be beneficial for further treatment.